1. Field of the Disclosure
The disclosure relates to an equalizer and an equalizing method. Particularly, the disclosure relates to an adaptive equalizer and an adaptive equalizing method.
2. Description of Related Art
Generally, when a high-speed transmitted signal is transmitted through a channel, signal intensity thereof is probably attenuated, which may cause reduction of the signal intensity and increasing of noise jitter, so that a bit error rate of a transmission result is increased, which may influence communication quality. FIG. 1 is waveform and eye diagrams of a signal transmitted in various parts of an electronic system. Referring to FIG. 1, after a signal S1 is enhanced by a driver 110 at a transmitting end of the electronic system 100, it enters a channel 130 for transmission, and before the signal enters the channel 130, according to an eye diagram of the output of the driver 110, it is known that the signal S1 has good signal quality. However, after the channel transmission, the signal S1 is attenuated at an output end of the channel 130 as that shown in an eye diagram of the output of the channel 130, and the signal quality thereof is deteriorated due to the attenuation and noise jitter.
In order to resolve the above problem, a commonly used method is to add a continuous time linear equalizer (CTLE) 120 at a receiving end of the electronic system 100. The CTLE 120 boosts high frequency gain for the signal S1 to compensate a channel loss, so as to improve the signal quality. According to an eye diagram of the output of the CTLE 120, it is known that the compensated signal S1 has similar good quality as that of the signal S1 output by the driver 110.
However, during an actual application, the channel loss is not fixed, and the conventional compensation method has to use an adaptive control device to detect whether the high frequency compensation is optimal. However, many existing structures have limitations in applying the adaptive control device due to, for example, an architecture thereof is too complicated, implementation of a transmission speed of gigabit bytes per second (Gbps) is hard to be achieved, and compensation accuracy of mass production is not high, etc.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the invention, or that any reference forms a part of the common general knowledge in the art.